This invention relates to a shoe sole structure, and more particularly to a ventilated shoe sole structure.
There has long been a need to design shoes to minimize, if not eliminate, the unpleasant odor that is generated during wear. Additionally, there is a need to design a shoe that will keep the wearer's foot cooler and drier. The normal shoe construction traps the air around the wearer's foot and permits the natural perspiration and body odor generated during the day to simply collect within the shoe. The shoe material becomes impregnated with this perspiration and odor and eventually both the wearer and those around him are subjected to this unpleasant occurrence.
There have been previous attempts to remedy this situation. For example, U.S. Pat. No. 2,552,711 (Dunker) discloses a boot that is provided with a spring-type pump arrangement that attempts to circulate exterior air into the toe region of the shoe. An air check valve is utilized to permit exterior air to be drawn into the region of the heel so that when the wearer takes a step, a leather plate is depressed which forces air into the toe region of the boot. A mechanical spring is placed in the heel of the boot to return the leather plate to its upper position.
This arrangement, however, requires the use of the check valve to ensure that the air is forced into the toe region of the shoe. Without the check valve, the exterior air would have tendency to fllow bback out the rear of the boot and not serve its intended purpose. The check valve is also located inside the heel of the boot and its ability to function may be impaired by the heel of the wearer pressing down on the leather plate. The inside configuration and dimensions of the shoe also change during each step. The heel of the wearer's foot actually moves up and down through the travel space through which the leather plate traverses to push the air toward the toe region. Thus maintaining a comfortable fit about the wearer's heel is not possible with this design. There likewise is no support for the middle region or the toe region of the foot since both of these areas change size up and down during each step by the wearer. The use of a spring under the wearer's heel also creates an uncomfortable foreign object inside the shoe which will cause discomfort to the wearer during each step. Eventually, the spring would actually wear through the leather plate and contact directly the underside of the wearer's heel causing direct discomfort not unlike walking on a rock. Finally this design is quite difficult to manufacture and assemble in that many parts not normally found in a shoe or boot must be added. Also, the failure of any of these moving parts will completely destroy the functionality of this shoe.
Another attempted remedy is shown in U.S. Pat. No. 3,050,875 (Robbins). This patent discloses a shoe sole comprised of a plurality of layers. The intermediate layer has a series of oval cavities interconnected by small passageways. The toe region of the sole has a plurality of small vents. When the wearer takes a step, the air inside the shoe is circulated from the heel of the shoe to the toe of the shoe and then upwardly through the vents. When the wearer's foot reaches then end of his step, the air recirculates backwardly from the toe of the shoe to the heel of the shoe.
The only external access &:o the intermediate sole cavities is through the small vents in the toe of the shoe. The only possible fresh, outside air that can be used for circulation comes in through the space between the wearer's ankle and the upper opening of the shoe. This outside air must actually pass over the wearer's foot on its way to the intermediate sole cavities. This air will already have been subjected to the odors present on the wearer's foot. This design actually requires a plurality of interconnected chambers to effect the circulation of the air. Much of the air that is flowing back and forth is the same air that has remains within the shoe and has already been subjected to the odors present on and around the foot of the wearer. The numerous cavities also results in large, irregular areas under the foot of the wearer which fails to provide adequate support to the wearer's foot and will cause discomfort during use.
Yet another proposed remedy is shown in U.S. Pat. No. 4,102,061 (Saaristo). Two small vents located in the center of the sole are disclosed as providing passageways for air to be vented to the interior of the shoe. The air intake, however, is located very close to the surface walked upon which increases the possibility that dirt or water may be sucked into the sole area thus contaminating the outside air and diminishing its ventilating effect. This design also utilizes a check valve to ensure flow is only in one direction which increases the possibility of premature failure of the design in the event of failure of the check valve. As with the other designs previously discussed, the interior surface of the shoe which is contacted by the bottom of the foot actually deforms to decrease the size of the chambers to effect the flow of air, but this deformation results in actual or potential discomfort to the wearer.
It is an object of the present invention to provide a shoe sole structure that effectively and efficiently ventilates the interior areas of a wearer's foot.
It is a feature of the present invention to utilize a single continuous transforming passageway to pump or feed fresh outside air from the heel region of the shoe forward to the toe region of the shoe. This is accomplished during each stride of the wearer and without the necessity of check valves or springs to effect the circulation of the air. Air that has been contaminated by the foot of the wearer is prevented from returning to the passageway by the flexible and unique design of the sole.
It is an advantage of the invention that fresh, uncontaminated air is pumped or fed to the interior of the shoe in order to cool and ventilate the foot of the wearer automatically with each step made by the wearer.